Roll polishing mechanism



Feb. 13, 1934. H. w. BRADLEY ET AL ROLL POLISHING MECHANISM Filed Feb. 18, 1932 3 Sheets-Sheet 1 1 NTO H Q w, We

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1934- H. w. BRADLEY El AL ROLL POLISHING MECHANISM Filed Feb. 18, 1932 3 Sheets-Sheet 2 [NV NTOR 0M4 @oM-Q lab gov/M1} ATTORNEY.

1934- H. w. BRADLEY El AL 1,946,927

ROLL POLISHING MECHANI SM Filed Feb. 18, 1932 3 Sheets-Sheet 3 W UBNVENTORS wwJZ QM 7J- J,

ATTORNEY Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE ROLL POLISHHNG MECHANISM tion of Ohio Application February 18, 1932. Serial No. 593,828

12 Claims.

This invention relates to roll grinding and roll polishing devices for maintaining a clean, smooth surface on rolling mill rolls, while the rolling mill is in operation, thus making it possible continuously to operate the rolling mill for extended periods of time without suspending the sheet rolling operation.

It is well known in the rolling mill industry that mill rolls, especially on sheet and tin plate mills accumulate adhering and imbedded scale particles. On account of the sliding action of the sheet upon the roll at the terrific pressure necessary for elongation, roll abrasions also accumulate. Every time the end of the material which is being rolled enters or leaves a pair of rolls there is always intensified pressure at the instant of the said entrance or egress therefrom, with the result that what in the industry are usually referred to as tail marks gradually ruin the roll surface. These surface defects of the rolls are inimical to the production of high grade sheets. With the advent of lacquer finishes and other extremely thin finishes for formed sheet metal products, it became a requirement that rolled metal sheets have a very smooth, even surface, thus making it necessary to polish the rolls so frequently that mill production was seriously hampered. It has been the practice in the past to stop feeding sheets or plates into the mill and to polish these rolls by hand, by rubbing the rolls, while rotating, with blocks of abrasive material, such as carborundum, or the like, until the rolls are smooth enough to again operate satisfactorily.

Several attempts have been made in the past to provide devices of a mechanical nature which will continually polish roll surfaces while in operation. Our experience has indicated that none of these devices will satisfactorily meet all the requirements of a roll polisher, especially on over and-under mills used in finishing hot rolling material from the modern strip mill. In order to finish hot rolling this strip material with only one heating, it is necessary to roll at high temperature and with large reductions per pass. Hence it has become necessary continually and vigorously to polish the surface of the rolls while the rolling operation is in progress.

Up to the present time we have been unable to secure an abrasive or grinding stone which does not glaze over and cease to function as intended; with the result that the surface thereof must be cleaned at regular intervals. The present device is so constructed that any stone-holder and its stone can be removed for cleaning without tools and with the mill in full production.

Another vital consideration in a successful and practical roll polisher is one which, so far as we know, has not heretofore been solved, viz., that of changing rolls. In the past, sheet manufacturers have limited the size of sheets to a few standard sizes, and thereby have been able to operate with but few different sized mills, making it unnecessary to change mill sizes frequently; but with the advent of all steel auto-bodies the subsequent demand for wide sheets, continued use of narrow sheets, and the general tendency for flat steel manufacturers to make sheets in all sizes, it is not uncommon to change from long to short rolls, or vice versa, frequently. Therefore, we provide a roll polisher which can be dismantled and removed from the mill by two experienced men in less than one minute, with no other tools than a hammer, steel rod or bar, or any means for knocking out the wedges.

Another advantage of the present invention is found in a plurality of independently adjustable stone-holders, which permit each stone to follow the contour of the rolls, thereby assuring even grinding and polishing over the entire surface of the roll, something which cannot be accomplished with one long continuous stone or a number of under the modern demands for extreme production.

Mill rolls for hot rolling are prepared slightly concave from end to end, and in operation as the rolls become heated, the central portions thereof are heated by the hot material and as a result expand until they are slightly convex from end to end. At that temperature at which the heat radiated from the rolls is approximately equal to that absorbed, a state of more or less thermal equilibrium is reached. Whenever the rolling op eration is suspended the rolls dissipate heat, and in so doing change contour. A roll polisher, therefore, to meet the exigencies placed upon it must be so effective that a suspending of the rolling operation to polish the rolls is unnecessary; It must also be so constructed that when the rolls are not subjected to variations in temperature, the abrasive blocks must bear evenly thereon. The invention herein described also provides means for changing this uniform pressure when it is necessary to grind one part of the roll surface more vigorously than the rest. To accomplish grind ridges in the roll, but that the stones have a tendency to free themselves of foreign matter, which when accumulated in sufficient quantities fills up or glazes the stone face, destroying its abrasive qualities. The preferred embodiment of reciprocating means for the stones is such as will impart to the abrasive grinding stones a horizontal velocity which varies, in order that the resultant or combined rubbing velocity due to the forward rotation of the roll face and the horizontal 2c velocity due to the reciprocation of the stone,

varies in direction in order that each part of the roll face is struck by the polishing block in a different direction in succeeding revolutions of the roll.

s We have also discovered that the reciprocation of the polishing blocks should be on such a cycle as to coincide with the cycle of rotation of the mill as infrequently as it is possible to attain.

Another purpose of this device is to provide a 39 roll polisher of the characteristics outlined above,

'which is strong and rigid, simple in construction, and one from which the stones can be readily removed for cleaning and replacing without interfering with mill operation; relatively simple in construction and of such a nature that it will operate under the extreme conditions required of such a device without other attention than occasionally cleaning the stones.

The present invention also provides a continu- 4o sous roll polisher which is adaptable to old mill housings without any change thereto, except a few tapped holes, and to housings with extremely narrow window notches for the shaft; and one which can be readily adjusted by the mill opterators, and which, when operatively attached to the mill, in no way interferes with the rolling of sheets or strips thereon. Other advantages of the invention will be pointed out from time to time with specific references to the drawings or parts thereof.

Figure 1 shows the side view of the mill with the polishing blocks of the lower roll in place, but with'only one complete assembly shown for the polisher for the upper roll. Some of the springs pr yielding means have been omitted in this view,

as have also two of the polishing blocks in order to better illustrate certain features of the device. While this view shows four polishing blocks assembled on the mill, it is understood that the number of blocks required varies with the length of the mill and we do not limit our invention in any way to the number of blocks shown. This figure is a somewhat conventional view of a twohigh rolling mill showing the roll polisher in Ioperative association with both the top and bottom rolls.

Figure 2 is an end view of a conventional rolling mill with one housing thereof removed, and the polisher sectioned on line B-B, in order to illustrate the operative position of the stones relative to the mill and illustrate the positions of the parts thereof with reference to each other.

Figure 3 is a partial view of the stone-holders illustrating the means of securing said holders to the reciprocating shaft, and also illustrating a method of securing the stones to the holder.

Figure 4 shows the preferred means of preventing the main shaft of the top roll polisher from rotation as well as illustrating a means of controlling the relative rotative position thereof with reference to the mill. Figure 5 also illustrates the method preferred for attaching the stripping fingers to the shaft.

Figure 6 shows the method which we employ to secure a member to the reciprocating shaft for the upper roll polisher against rotative and longitudinal motion relative thereto, the said member also acting as the fixed point against which the spring reaction bears, in order to force the polishing block against the upper roll.

Figure 7 is a fragmentary view illustrating a convenient method of attaching the roll polisher to the housings of the mill. Referring again to Figure l, the mill housings 1-1 are conventional, as are the rolls 2-2. We provide for the recoprocation of the shafts 33 by a gear reducer 4, through crank 5, pin 6 and connecting rod 7. The gear reducer can be driven by any conventional prime mover such as a motor, not shown on the drawings. While we have illustrated this method of supplying reciprocating motion to the shafts, other means would suggest. themselves to those skilled in the art, but would in no way depart from the spirit of the invention. The shafts 33 ar connected by a bracket 23.

Referring again to Figure 4; key 25 prevents arm 22 from rotating on 3, and 22 is held in rotative relation to 23 by the adjustment 24.

In any roll polisher for successful adaptation for rolling mill work, it is necessary that said polisher be speedily removable from the mill. In order to accomplish this purpose, we provide a mounting as illustrated in Figure 1 and also in Figure '7, wherein we have shown the end bearings for the reciprocating shafts secured to the mill housings by studs 9a tapped therein and holding the bearing plates 8, Figure 7, securely to the housing by wedges 9. By knocking out these wedges, the bearing plate 8 for the polisher shafts can be speedily removed. On account of the reciprocation of th shafts 3, it is necessary to prevent longitudinal motion thereon of the parts affixed thereto, and at the same time have such parts so connected that removal therefrom can be accomplished without interfering with mill operation. We accomplish this by the crescent shaped hook 10a of the holder 10 shown in Figures 1, 2 and 3. The preferred method of securing the polishing block 11 to the holders 10 is illustrated in Figure 3. The stone is cast with a depression which sets snugly down over a raised key 102) in the holder 10 (which prevents hori ontal motion relative thereto) and is held firmly in place by the wedge member 12, clamping the stone 11 in the conventional manner. On account of the different character of materials rolled on a rolling mill, it is expedient and often necessary to vary the amount of pressure on the polishing block in order that the amount of grinding of the roll can be actively controlled. On the polisher for the bottom roll, this can be effected most easily by a weight 13, the position of which on the holder can be selectively controlled.

I On account of the space required ror the egress of a pack and the sending of the pack back from the mill in the so-called over-and-under method of rolling, the use of weights to secure pressure of the stone against the upper roll is inconvenient;

Ill

and we substitute therefore in the upper roll polisher an organization comprising the member 14, shown in Figures 1, 2 and 6, which is held against rotative motion on shafts 3 by the milled parallel sections of these shafts shown in Figures 1 and 5 and against radial motion by the member 2211 (Fig. 6), which fits into a keyway 222) on the shaft 3. Further horizontal motion of the block holder 10 on the shaft 3 is prevented by providing a raised place St: on the shaft between each of the said blocks.

The pressure of spring 16 which pushes the block holder and the block contained therein inwardly against the roll can be varied by the position of the nut 15 on the ring bolt 17 in Figure 2. In order to provide for quick removal and disassembly of this apparatus, the upper end of the spring 16 rests against a member 16a with a spherical seat, in order that, as the block wears, the spring and the rod or bolt 17 will stay in position. The upper end of the upper stone-holders is forked so that, for disassembly, the operator may grasp the member 1'7 in his hand and pull it back from engagement with the stone-holder 10, thereby releasing the stone-holder 10 for removal from the mill.

On account of the tendency of sheets to follow the curvature of the mill roll, it is necessary to provide standard stripping fingers 18 or their equivalent, which form no part of this invention; and we also provide upper stripping fingers 19, Figure 5, which engage the shaft 3 and are held in position by the rod 20 attached thereto, which rests between the raised parts 21 of the arm 14 in Figure 6. To illustrate the disassembly and the speed at which it can be accomplished in the event of a mill change, the bottom stone-holder, by grasping the handle of the weight 13, can be lifted and removed from the bottom shaft 3 of the polisher. The spring holder 17 shown in Figure 2 can be grasped and pulled out of the slot on the block holders l0, whereupon the block holders can be lifted out. The stripping finger 19 can then be lifted and removed from the upper shaft 3; and the curved member 14, which serves the dual purpose of a pivot for the spring and a skid for aiding the catcher in delivering the pack back over the mill, can be lifted vertically from the shaft. The wedges 9-9 are then removed, plates 8 removed, the crank 5 removed from pin 6 by loosening a wing nut or its equivalent; and the balance of the assembly can then be withdrawn from the mill.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is:

l. A roll polishing device for rolling mills comprising a plurality of abrasive blocks, one face thereof adapted to engage a roll, independent means for holding each of the said blocks against the roll with an independently adjustable yielding pressure, and means for reciprocating the blocks relative to the roll.

2. A polishing device for rolling mill rolls, comprising a plurality of polishing blocks disposed substantially in line for each of the rolls of the mill and adapted to engage the longitudinal curvature of the said rolls regardless of contour; separate means for holding each of the said blocks independently against the roll with selectable yielding pressure, and means for reciprocating said blocks relative to the rolls.

3. A roll polishing device for a, rolling mill comprising a plurality of abrasive blocks disposed in such a manner that one set of blocks is held yieldingly against each of the rolls of the mill, independent pressure adjusting means for each of said blocks, and means for imparting an endwise reciprocating motion to said blocks, said means causing the velocity of the said reciprocating movement to vary continually from the beginning to the end of each stroke.

4. A roll polishing device for a rolling mill comprising a plurality of abrasive blocks disposed substantially end to end for engaging the longitudinal curvature of the upper roll substantially throughout its length, a plurality of abrasive blocks disposed substantially end to end for engaging the longitudinal curvature of the lower roll substantially throughout its length, means holding each of the said blocks independently against the rolls with an adjustable yielding pressure, and means for reciprocating the said blocks relative to the said rolls.

5. A roll polishing device for a rolling mill, comprising a plurality of abrasive blocks for each of the rolls thereof, the said abrasive blocks being so disposed with relation to the rolls that one face thereof may be placed in yielding engagement with said rolls; means for selectively varying the pressure of each of the polishing blocks independently against the roll in order to control the rate of grinding or polishing on any part of the said roll face, and means for imparting an endwise reciprocating motion to the blocks, the velocity of the said reciprocating movement varying continually from the beginning to the end of each stroke.

6. A roll polishing device for rolling mills com prising a plurality of abrasive blocks disposed end to end and engaging the longitudinal curvature of a roll throughout its length regardless of contour, the said blocks being independently supported and held against the said rolls with selectively adjustable yielding pressure means, an independently removable holder for each of the said blocks, and means for securing the polishing blocks therein, a common support for the holders of the abrasive blocks which engage the upper roll and means for securing the holders thereto, a common support for the holders of the abrasive blocks which engage the lower roll and means for securing the holders thereto, bearings detachably clamped to the mill housing by wedges for the said supports, the said supports held against rotative and longitudinal motion relative to each other, and means for imparting an endwise reciprocating motion to the said supports.

'7. A roll polishing device for rolling mills comprising a plurality of abrasive blocks for a lower roll thereof, a holder for each of the said blocks having means to hold the blocks firmly therein, a common support for said holders, the said holders rotatably but not slidably mounted on the said support, bearings for the said supports, and a weight adjustably and slidably mounted upon each holder for the purpose of exerting a yielding pressure upon the said block against said roll regardless of roll contour.

8. A roll polishing device for rolling mills comprising a plurality of abrasive blocks for each of the rolls thereof, a holder for each of the said blocks having means to hold the blocks firmly therein, a common support for the holders of the abrasive blocks which engage the upper roll; a common support for the holders of the abrasive blocks which engage the lower roll, the said block holders rotatably but not slidably mounted on the said supports, bearings for the said supports, independent weights adjustably and slidably mounted upon the holders for the lower blocks, independent spring pressure means for exerting yielding pressure upon the blocks bearing against the roll regardless of roll contour, and means for reciprocating the said supports in an endwise direction with respect to the mill rolls.

9. A roll polisher for each of the rolls of a rolling mill comprising a plurality of abrasive blocks disposed end to end and engaging the roll sub-= stantially throughout its length, a plurality of block holders with means for holding said abrasive blocks therein, a support spanning the mill with the said block holders rotatably but not slidably mounted thereon, fixed members detaohably but non-slidably and non-rotatably mounted on said supports, the said fixed members being shaped to guide a sheet moving from the delivering to the feeding side of the mill over the top roll thereof, means of supplying a yielding and adjustable separating force between the said members and the said block holders for the purpose of pressing the abrasive blocks individually against the roll regardless of the roll contour.

10. A roll polisher for each of the rolls of a j rolling mill comprising a plurality of abrasive blocks disposed end to end and engaging the roll substantially throughout its length, a plu rality of block holders with means for holding saidabrasive blocks therein, a support spanning the mill with the said block holders rotatably but not slidably mounted thereon, fir-zed members detachably but non-slidably and non-rotatably mounted on said supports, the said fixed members being shaped to guide a sheet moving from the delivering to the feeding side of the mill over the top roll thereof, means of supplying a yielding and adjustable separating force between the said members and the said block holders for the purpose of pressing the abrasive blocks individually against the roll regardless of the roll contour, a plurality of guide bars detachably mounted on the said support, one end of said guide bars located adjacent the roll, and means for controlling the relative rotative position of the said support with respect to the housings of the mill.

11. In combination with a rolling mill, 2. roll polisher comprising a plurality of abrasive blocks, a plurality of block holders with means for holding the said blocks therein, a journaled support spanning the mill with the said block holders rotatably but not slidably moiuited thereon, fixed members detachably but neither slidably nor rotatably mounted on said supports, the said fixed members being shaped to guide a sheet moving from the delivering to the feeding side of the mill over the top roll thereof, means of supplying a yielding and independently adjustable force to the said members and the said block holders for the purpose of pressing the abrasive blocks independently against the roll regardless of the roll contour, a plurality of guide bars detachably mounted on the said support, one end of said guide bars almost engaging the roll, means for controlling the relative rotative position of the said support with respect to the housings of the mill, and means for imparting an endwise reciproeating motion to the said supports.

12. In combination with a rolling mill, a roll polisher comprising a plurality of abrasive blocks, a plurality of block holders with means for holding the said blocks therein, a journaled support spanning the mill with the said block holders rotatably but not slidably mounted thereon, fixed members detaohably but non-slidably and nonrotatably mounted on said support, the said fixed members being shaped to guide a sheet moving from the delivering to the feeding side of the mill over the top roll thereof, means for supplying a yielding and adjustable separating force between the said members and the said block holders, a plurality of guide bars detachably mounted on the said support, one end of said guide bars engaging the roll, means for controlling the relative rotative position of the said support with respect to the housings of the mill, a second set of blocks, a support, holders for said blocks rotatively mounted on said support, independent weight means engaging said holders, and means for simultaneously reciprocating said supports.

HOWARD W. BRADLEY. PAUL H. LONG. 

